Thuban/Model/proj.py

# Copyright (c) 2001 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

from Thuban import _

from types import StringTypes

import Projection
BaseProjection = Projection.Projection
del Projection

PROJ_UNITS_METERS  = 1
PROJ_UNITS_DEGREES = 2

class Projection(BaseProjection):

    """A proj4 projection object that remembers the parameters"""

    def __init__(self, params, name = None):
        """Initialize the Projection with a list of 
        'parameter=value' strings and an optional name. If 'name' is
        None, the name will be set to 'Unknown' in the local language.
        """

        BaseProjection.__init__(self, params)

        if name is None:
            self.name = _("Unknown")
        elif isinstance(name, StringTypes):
            self.name = name

        self.params = params

    def ForwardBBox(self, bbox):
        """Return the bounding box of the corners of the bounding box bbox
        """
        # This is not really the correct way to determine the bbox of a
        # projected shape, but for now it works well enough
        llx, lly, urx, ury = bbox
        xs = []; ys = []
        x, y = self.Forward(llx, lly)
        xs.append(x); ys.append(y)
        x, y = self.Forward(llx, ury)
        xs.append(x); ys.append(y)
        x, y = self.Forward(urx, ury)
        xs.append(x); ys.append(y)
        x, y = self.Forward(urx, lly)
        xs.append(x); ys.append(y)
        
        return min(xs), min(ys), max(xs), max(ys)

    def GetName(self):
        """Return the name of the projection."""
        return self.name

    def GetParameter(self, param):
        """Return the projection value for the given parameter.

        If 'param' exists as a valid parameter then the returned
        value is a string with that value. If the parameter doesn't
        exist an empty string is returned.
        """

        for pair in self.params:
            p, v = pair.split("=")
            if p == param:
                return v

        return ""

    def GetAllParameters(self):
        """Return list of 'parameter=value' strings"""
        return self.params

    def GetProjectedUnits(self):
        if self.GetParameter("proj") == "latlong":
            return PROJ_UNITS_DEGREES
        else:
            return PROJ_UNITS_METERS

    def __repr__(self):
        return self.name + ": " + repr(self.params)

class ProjFile:

    def __init__(self, filename):
        """Intialize the ProjFile.

        filename -- name of the file that this ProjFile represents.
        """

        self.__projs = []

        self.SetFilename(filename)
    
    def Add(self, proj):
        """Add the given projection to the end of the file. If 'proj'
        already exists, it is replaced in the same location as the
        original projection.
        """

        try:
            #
            # see if the projection already exists.
            # this only works if Projection doesn't override __eq__
            #
            self.__projs[self.__projs.index(proj)] = proj
        except ValueError:
            self.__projs.append(proj)

    def Remove(self, proj):
        """Remove the object proj from the projection file.

        Raises a ValueError is proj is not found.
        """

        self.__projs.remove(proj)

    def Replace(self, oldproj, newproj):
        """Replace the object 'oldproj' with 'newproj'.
        
        Raises ValueError if oldproj is not in the file.
        """

        #
        # see if the projection already exists.
        # this only works if Projection doesn't override __eq__
        #
        self.__projs[self.__projs.index(oldproj)] = newproj

    def GetFilename(self):
        """Return the filename where the ProjFile was read or will be
        written to.
        """

        return self.__filename

    def SetFilename(self, filename):
        """Set the filename where the ProjFile will be written to."""
        self.__filename = filename

    def GetProjections(self):
        """Return a list of the projections in the order they were read
        from the file or will be written.

        This is not a deep copy list, so any modifications made to the
        Projection objects will be written to the file.
        """

        return self.__projs

1	# Copyright (c) 2001 by Intevation GmbH
2	# Authors:
3	# Bernhard Herzog <[email protected]>
4	#
5	# This program is free software under the GPL (>=v2)
6	# Read the file COPYING coming with Thuban for details.
7
8	__version__ = "$Revision$"
9
10	from Thuban import _
11
12	from types import StringTypes
13
14	import Projection
15	BaseProjection = Projection.Projection
16	del Projection
17
18	PROJ_UNITS_METERS = 1
19	PROJ_UNITS_DEGREES = 2
20
21	class Projection(BaseProjection):
22
23	"""A proj4 projection object that remembers the parameters"""
24
25	def __init__(self, params, name = None):
26	"""Initialize the Projection with a list of
27	'parameter=value' strings and an optional name. If 'name' is
28	None, the name will be set to 'Unknown' in the local language.
29	"""
30
31	BaseProjection.__init__(self, params)
32
33	if name is None:
34	self.name = _("Unknown")
35	elif isinstance(name, StringTypes):
36	self.name = name
37
38	self.params = params
39
40	def ForwardBBox(self, bbox):
41	"""Return the bounding box of the corners of the bounding box bbox
42	"""
43	# This is not really the correct way to determine the bbox of a
44	# projected shape, but for now it works well enough
45	llx, lly, urx, ury = bbox
46	xs = []; ys = []
47	x, y = self.Forward(llx, lly)
48	xs.append(x); ys.append(y)
49	x, y = self.Forward(llx, ury)
50	xs.append(x); ys.append(y)
51	x, y = self.Forward(urx, ury)
52	xs.append(x); ys.append(y)
53	x, y = self.Forward(urx, lly)
54	xs.append(x); ys.append(y)
55
56	return min(xs), min(ys), max(xs), max(ys)
57
58	def GetName(self):
59	"""Return the name of the projection."""
60	return self.name
61
62	def GetParameter(self, param):
63	"""Return the projection value for the given parameter.
64
65	If 'param' exists as a valid parameter then the returned
66	value is a string with that value. If the parameter doesn't
67	exist an empty string is returned.
68	"""
69
70	for pair in self.params:
71	p, v = pair.split("=")
72	if p == param:
73	return v
74
75	return ""
76
77	def GetAllParameters(self):
78	"""Return list of 'parameter=value' strings"""
79	return self.params
80
81	def GetProjectedUnits(self):
82	if self.GetParameter("proj") == "latlong":
83	return PROJ_UNITS_DEGREES
84	else:
85	return PROJ_UNITS_METERS
86
87	def __repr__(self):
88	return self.name + ": " + repr(self.params)
89
90	class ProjFile:
91
92	def __init__(self, filename):
93	"""Intialize the ProjFile.
94
95	filename -- name of the file that this ProjFile represents.
96	"""
97
98	self.__projs = []
99
100	self.SetFilename(filename)
101
102	def Add(self, proj):
103	"""Add the given projection to the end of the file. If 'proj'
104	already exists, it is replaced in the same location as the
105	original projection.
106	"""
107
108	try:
109	#
110	# see if the projection already exists.
111	# this only works if Projection doesn't override __eq__
112	#
113	self.__projs[self.__projs.index(proj)] = proj
114	except ValueError:
115	self.__projs.append(proj)
116
117	def Remove(self, proj):
118	"""Remove the object proj from the projection file.
119
120	Raises a ValueError is proj is not found.
121	"""
122
123	self.__projs.remove(proj)
124
125	def Replace(self, oldproj, newproj):
126	"""Replace the object 'oldproj' with 'newproj'.
127
128	Raises ValueError if oldproj is not in the file.
129	"""
130
131	#
132	# see if the projection already exists.
133	# this only works if Projection doesn't override __eq__
134	#
135	self.__projs[self.__projs.index(oldproj)] = newproj
136
137	def GetFilename(self):
138	"""Return the filename where the ProjFile was read or will be
139	written to.
140	"""
141
142	return self.__filename
143
144	def SetFilename(self, filename):
145	"""Set the filename where the ProjFile will be written to."""
146	self.__filename = filename
147
148	def GetProjections(self):
149	"""Return a list of the projections in the order they were read
150	from the file or will be written.
151
152	This is not a deep copy list, so any modifications made to the
153	Projection objects will be written to the file.
154	"""
155
156	return self.__projs
157
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svn:keywords	Author Date Id Revision